براغي سوكيت كاب من HOLO-KROME 72182 3/8-16 X 4-1/2" | محرك سداسي سوكيت | فولاد سبائكي مع أكسيد أسود حراري (50 / عبوة)

The black oxide finish on these screws is really uniform and seems durable—installed a few in a jig fixture with no issue. Threads were clean and started easily by hand before tightening with the hex key.

Needed a long 4-1/2" cap screw for a custom tooling fixture, and the black oxide finish on these gives them a nice, durable look. The threads engaged smoothly without any binding, which saved me a lot of time. Perfect for heavy-duty use so far.

Been using these in my jig builds and the black oxide finish has held up through repeated clamping without a speck of rust. Threads seated cleanly into the tapped holes with no binding, and the alloy steel drove down tight without a hint of flex.